INDIANAPOLIS -- No one told Katie Ledecky you are not supposed to set world records apart from championship meets while in the middle of heavy training.

In her first meet as a professional swimmer, she lowered her own world record in the 1,500-meter freestyle by five seconds to 15 minutes, 20.48 seconds Wednesday night at the Natatorium at IUPUI.

It was the first event of the TYR Pro Swim Series meet, which continues through Saturday.

Ledecky, a five-time Olympic gold medalist, hit her fist in the water and stuck out her tongue after touching the wall and seeing the scoreboard. The world record was the 19th set at the Natatorium, which opened in 1982.

It was Ledecky's first world record since the 2016 Rio Olympics. It also ended her longest drought between world records since setting the first of her 14 in 2013. This is the sixth time she has broken the world record in the 1,500 freestyle, which debuts as an Olympic event at Tokyo in 2020.

Ledecky's previous record was 15:25.48 at the 2015 World Championships in Kazan, Russia.

Email IndyStar reporter David Woods at david.woods@indystar.com or call (317) 444-6195. Follow him on Twitter: @DavidWoods007.